Fractional distillation of crude petroleum and other hydrocarbons



A. F. G. C. P. J. VON GROELING.

FRACTIONAL DISTILLATION 0F CRUDE PETROLEUM AND OTHER HYDROCARBONS.

APPLICATION FILED APR. 22. I916- 0. m W T. mm "mm .Nm. RN R Q n4 we asJn g Mm n 4 m "4. am M 5 6m W M mww mu 8 1 I 7 2 3 1 A A. F. G. C. P. J.VONv GROELING. I FRACTIONAL DISTILLATION 0F CRUDE PETROLEUM AND OTHERHYDROCARBONS.

APPLICATION FILED APR- 22. I916.

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* APPLICATION FILED APR. 22, I9I6. 1,327,1 Patented Jan. 6,1920.

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APPLICATION FILED APR. 22. I916.

Patentd Jan.

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UNITED STATES PATENT OFFICE.

ALBRECHT FREDERICH GEORG CARL PAUL J OSEF VON GROELING, OF NEW YORK, N.Y., ASSIGNOR T0 ATLAS PROCESS COMPANY, INC, OF NEW YORK, N. Y., ACORPORATION on NEW YORK.

FRACTIONAII DISTILLATION OF CRUDE PETROLEUM AND OTHER HYDROCARBONS.

Specification of Letters Patent.

Patented Jame, 1920.

Application filed April 22, 1916. Serial No. 92,807.

To all whom it may concern:

Be it known that I, ALBREoH'r, FREDERICH GEORG CARL PAUL JosEF VONGROELING, a subject of the Emperor of Austria, and a resident of NewYork, in the county and State of New York, have invented certain new anduseful Improvements in Fractional Distillation of Crude Petroleum andother Hydrocarbons, of which the following is a full, clear, and exactdescription.

The invention that forms the subject of thepresent application relatesto the distillation of crude petroleum or similar oils,

' and its chief object is to provide an improved apparatus for thepurpose whereby breaking up or cracking of distillates is practically,if not entirely, avolded, thus maintainmg the natural composition of thesame, with the best possible qualities as regards specific gravity,fiash-point, color, viscos ty, and smell. A further object is theavoidance of evaporation losses in the distillation, formation of tarrysubstances (asphaltum and coke or carbon) in the later products, andformation of so-called fire-paraffins. The process is eitherintermittentor continuous, asdesired, and is performed entirely invacuo, with the exception that the lighter fractions, such as gasoleneand kerosene, mayif desired be distilled at. ordinary pressure. 1

A convenient and effective apparatus for the purpose is illustrated,somewhat diagrammatically, in the accompanying drawings, in which-Figure 1 is a plan view of the entire plant, omitting only the bo ileror other generator by which steam is produced for heating the still orstills.

Fig. 2 is a side view of the same, from the bottom of Fig. 1, and

Fig. 3 is an end view from the left of Fig. 2.

Fig. 4 is a cross seCti0I1, about on line 4-4 of Fig. 1. i

Fig. 5 is a detail view of a barometric system for maintaining asubstantially constant degree of vacuum over the apparatus by regulatingthe operation of the pump or Fig. 8 is a cross section on line 8 8 ofFig. 6.

Fig. 9 is an end view of the still shown in livered by the boiler orgenerator, is supplied to the still or stills for heating the same.

Fig. 11 is a centrallongitudinal section of one of the vacuum receiversinto which the distillates are received for subsequent delivery tosuitable storage tanks or vessels, not shown.

The number of stills provided may be one or more. In the plantillustrated I have shown six, designated A, B,-C, D, E, F. Each is inthe form of a cylinder, arranged horizontally, with one or more vaporcollecting domes a, b, c, d, e, f. The stills are arranged in cascade,and are connected by pipes 10, 11, to the pipe 12 through which they aresupplied with the crude oil, the latter being drawn in by the vacuum,produced as hereinafter described. In each case the pipe 11 is extendeddown to the lower portion of the still (see Fig. 4) so that the residuecan flow from one still to the next, and finally to the residue cooler13.

By means of valves 14, 15, in the pipes 10,

11, 12, the rate of flow can be accurately regudesired by opening itsvalve 15 and closing its valves 14c. A drain pipe 16, connected to thebottoms of the stills through valved connections 17, is provided for thepurpose of draining the stills into the vessel 18 when desired. Thestills 1. ay be arranged on a level instead of in cascade; particularlyif 'the apparatus is to be used only for discontinuous working, in whichcase the connections 11 may be omitted.

The stills are heated by internal steamcoils 18, 19, Figs. 6, 7 ,8,connected by valved pipes 20,21 to, the steam main 22. By adjustment ofthe valves in said pipes 20, 21, the flow of steam to the heating coils,and hence the distilling temperature, indicated by thermometers, as T,Figs. 6 and 9, can be regulated as desired for each still. lo permitaccurate temperature regulation the steam should be supplied to the main22 at means for regulation of the pressure delivered, as for example theball and lever construction indicated in Fig. 10. The reducing valvesconstitute convenlent and eflective means for maintaining a pressure(and hence temperature) in the steanrchamber somewhat higher than in thestill-heating coils but lower than in the steam-generator. On top of thesteam chamber is a safety valve 26, a self-registering manometer 27, anda self-registering thermometer 28.

Water from condensation of steam in the heating coils 18, 19, isdischarged through an outlet 29, Figs. 6 and 7, and delivered to asuitable receptacle, not shown. Sightgages, as S, Fig. 9, are providedto indicate the liquid level in the stills.

It is at times desirable to inject live steam into the contents of thestills, or one or more of them, and for this purpose each still isprovided with a perforated pipe-30, Figs. 6 and 7, extendinglongitudinally near the bottom. These'perforated pipes are con- .nectedby valved pipes 31 to a pipe 32 which is itself connected to the steammain 22 through a valve 33.

The stills are not set in masonry, but are separately supported. They,are, however thoroughly heat-insulated by means of suitable jackets orcoverings. To avoid confusing the drawings these insulating jackets arenot shown. 1

The distillation is fractional, and hence the temperatures varyaccordingly, the ighter fractions coming off early in the series, forexample in the stills A and I3. Inasmuch as more or less of the heavierfractions may come off at the same time, dephlemgators of any suitablekind are provided to receive the vapors from such still as for instancecoolers of the tray type indicated at 34, Figs. 1, 2 and 3. The vaporsfrom the domes a, 7), enter the coolers at points near the bottomthrough pipes 35, and the light'vapors or gases pass out at the topwhile the heavier are condensed and flow back to the stills throughvalved pipes 36. Thelight vapors are conducted by pipes 37 to separatecondensers 38, 39, more fully described hereinafter. From the remainingstills thevapors pass from the domes to suitable air-cooled condenserscomposed of horizontal pipes 40, connected at one end to parallel pipes41, which are in turn connected to similar pipes 42. The three pipesnamed are of successively smaller diameter, and the first two areprovided with internalair pipes, as 43, 44, Fig. 1, open at the rear tothe atmosphere and at the front provided with vertical stacks orchimneys 45, for creating a draft for drawing air through the internalpipes. Ordinarily the natural draft thus obtained is sufficient, withoutthe use of fans or blowers.

From the condensers 404142 the proclucts flow through outlet pipes 46,47, 48, to the coolers 49, 50, 51, 52.

The condensers 38, 39, and the coolers 49, 50, 51, 52, are of similarconstruction, and may be provided with internal pipes (not shown) forwater circulation, connected through valves to a valved supply pipe 53.From the condensers 38, 39, and coolers 49, 50, 51, 52, the products runthrough sightglasses 54 to the vacuum receiving tanks 55, 56, 57, 58,59, 60, which are connected together by a pipe 61. Valves 62 63, areprovided so that the product of each still. can be delivered to its ownreceiver, or the fractions or products of neighboring stills can bedelivered to the same receiver, as desired. The vacuum receivers are alllike that shown in Fig. 11, which is in the form of a horizontal drum,provided at one end with a sight-gage 64 for showing the height of theliquid contents. When the contents of the receiver are to be removed thevalves 65 and 66 are closed and the cook 67 is opened to admit air,after which the liquid can be drawn off through the valved outlet pipe68. As previously stated, all the elements of the apparatus,the stills,coolers, condens-' ers, and receivers,-are, preferably, under vacuum.For this purpose the vacuum receivers 55, 56, 57, 58, 59, 60- areconnected (through the valves 66) to a pipe 69 which is in turnconnected to a suitable vacuum pump indicated at 70, driven by anyconvenient means as for example an electric motor 71. The pipe 69 isalso connected to the residue receivers 71, so that the latter, and theresidue cooler 13, with which they are connected, are alsounder vacuum.In the case of the lighter fractions, for example those coming off inthe stills A and B, the vacuum can be dispensed ith, as by propermanipulation of the valves 65, 66, 67.

The use of vacuum permits low distilling temperatures, and thetemperature used to obtain any given fraction depends upon the degree ofvacuum under which the distillation is effected. It is thereforeimportant to have the vacuum under control, so that it can be keptconstant. For this purpose any suitable and convenient controlling orregulating means, preferably automatic in action, as for example adevice which is responsive to change in the degree of vacuum and inaccordance therewith varies the rate of operation of the vacuum pumps.Such acontrolling system is illustrated diagrammatically in Fig. 5, andcomprises a U-shaped mercurial barometer'72, having a short-"leg whichis open and a long leg which is connected to the vacuum pipe 69 by avalved pipe 73, Fig. 1. Sealed in the longer leg is a series of platinumcontacts, of any desired number depending upon how closely it is desiredto regulate the vacuum. Three such contacts are 'shown, designated by74, 75, 76, connected to relay magnets 77, 78, 79, respectively, whichlatter are also connected through a battery 80 to a common returncontact 81 in the wall of the barometer opposite contact 74. Thecontacts for the relay armatures are connected to taps brought out froma resistance connected in the circuit by means of wires 82, 83, whilethe armatures themselves are connected in parallel directly to the Wire82. Assuming that the vacuum is sufficient to bring the mercury up tothe contact 74, it will be seen that the circuit of magnet 77 iscompleted andthe magnet energized, thereby raising its armature andcutting resistance into the circuit. If, now, the vacuum is insufiicientto hold the mercury at that point the column will fall, and when contact74% is uncovered the magnet is deenergized, whereupon the resistance iscut out and'the motor speeds up. On the other hand, if the mercurycontinues to rise it will reach contacts 75 and thus cut more resistanceinto the circuit, causing the motor to slow down. The motor of coursehas the usual manually operated controller (not shown) so that its speedcan also be controlled by hand to regulate the vacuum.

As previously stated, difi'erent temperatures are used in the stills,according to the products that are to be distilled out, low temperaturesbeing permitted-by reason of the vacuum, and hence cracking or breakingup of distillates is practically eliminated. Accurate regulation of thetemperature in the several stills is of the highest importance, and itis for this reason that steam-heating is used. Other heating means, forexample, electrical, may, however, be employed. The lightest product ofcourse comes off in the still having the lowest temperature, say stillA, the next in still B, and so on down the series. The differentiationof products is in general sharp, so that the distillates are allfinished products in that no further refining i's'required to fit themfor the market, except that all are usually to be filtered throughsuitable material, such as fullers earth, or

kieselguhr. If carefully done, this 'filtration sufiices to make thedistillates water white,

or at least light and agreeable in color and smell. Washing with acid isunnecessary, but if age should impart a yellowish tinge to any product aweak acid treatment is suf ficient to bleach it out. The transitionproducts between kerosene and lubricating oil are of-high quality,usable as high grade slightly viscous lubricants or for medicalpurposes, as they are' odorless and contam no noxious by-mixture. Thelubricating-"oils I can be converted into so-called Russian white oilswith no further treatment but filtration, and are quite neutral and fitfor bodily'internal use. The final residue, (the so-called cylinderstock), can be distilled if desired, but simple filtration is usuallysufficient. It contains no tarry matters, such as asphaltum'. Ifparaffin wax is present in the crude oil' it is not increased by theproduction of socalled fire parafiins. The wax crystals are easilyremoved by filtration, as there is no fire paraflin to interfere. Thewhole treatment of the paraflin wax is simplified, since it is confinedto a narrow fraction of the lubricating oils, and the final residue (thecylinder stock) is free from paraffin wax. In most cases the paraffinwax can be removed by simple filtration, and, if necessary, a shortsweating process.

In discontinuous or periodic working, the differentiation of theproducts is so sharp that redistillations need never be necessary;though between the kerosene fraction and the so-called gas oil fraction,part of the distillate may sometimes appear with traces of a neighboringfraction, in which case the lighter can be blown out with live steam.

As will be readily understood, the temperatures and the degree ofvacuum, needed for the best results, depend largely on the nature of thecrude oil which is to be treated, and hence no definite rule can begiven as to these particulars. They are, however, readily found byexperience for any given oil. In general the vacuum should be as high aspossible, that is, the pressure in the stills and other parts of theapparatus should be as low as practicable.

It is to be understood that the invention is not limited to the detailsof apparatus and procedure herein specifically described,

since these can be modified without depar 'nected with the receivers forcreating a high vacuum in said stills, condensers, and receivers;automatic means for controlling the vacuum-producing means to maintainthe degree of vacuum constant; steam-heating coils in the stills; asource of steam connected to the coils; automatic means for maintainingthe steam in said source at constant pressure, and means for regulatingthe supply-of steam to the coils, independently for each still, toaccurately regulate the distilling temperature therein.

2. In apparatus for distilling crule etroleum, comprising a, pluralityof stil s;

/ condensers and receivers; automatic means for controllingthfevacuum-producing means to maintain the vacuum substantially constantin degree; and still-heating means permitting independent control of thedistilling temperatures in the several stills.

3. An apparatus for distilling crude petroleum, comprising a pluralityof stills;

condensers connected with the respective stills; receiversconnected Withthe respective condensers; means for producing vacuum in the stllls,condensers, and rece1v ers; steam-heating coils in the several stills;

a steam main; connections from-:the steam main to the steam-heatingcoils, having means for regulating the supply of steam to the coils toaccurately control the dis tilling temperatures of the stillsindependently; and means for supplying steam to said main atsubstantially constant pressure.

In testimony whereof I hereunto afiix my signature.

ALBRECHT FREDERICH GEORG CARL PAUL JOSEF VON GROELING.

